Effect of Mo on the High Temperature Oxidation Behavior of Co-Al-W Based Alloys
2 at.% and 4 at.% Mo were added to Co-9Al-9W-2Ta-0.02B alloy to replace W (hereafter referred to as the alloys of 2Mo and 4Mo,respectively; Mo-free alloy was referred to as the 0Mo alloy).The effects of Mo additions on the high temperature oxidation behavior of the alloys at 800℃ in air have been studied.The results indicated that,after oxidation in air at 800℃ for 100 h,the oxide film of the 0Mo alloy remained intact,but the cracking and spallation of the oxide film took place in the alloys of 2Mo and 4Mo.Oxidation kinetic curves revealed weight gain per unit area of the 0Mo alloy was 36.86 mg·cm-2,which was lower than that of the alloys of 2Mo (65.16 mg·cm-2) and 4Mo (48.54mg·cm-2).These suggested that the 0Mo alloy displayed superior oxidation resistance compared to the alloys of 2Mo and 4Mo caused by the formation of volatile MoO3 oxide,and sharp compressive stress formed in the outer layer during the oxidation.The oxide layer was composed of three layers of the Co3O4 + CoO outer layer,middle complex oxide layer containing Co,Al and W (Mo),inner Al2O3 layer and γ/Co3W zone adhere to the γ/γsubstrate.
Molybdenum Co-based superalloy High-temperature oxidation Oxide layer
Fei Fan Hao Sun Di Zhao Jiangbo Sha
School of Material Science and Engineering, Beihang University, Beijing 100191, China
国际会议
the Chinese Materials Congress 2012(2012年中国材料大会(CMC2012))
太原
英文
754-759
2012-07-13（万方平台首次上网日期，不代表论文的发表时间）